Indicates if sidebar should listen to keyboard.

<div class="definition">
    Boolean, default = true
</div>

If <span class="argument">.keyboard</span> property is set to true, the sidebar will add event listener to listen for
keyboard events. There are several keyboard keys linked to the sidebar actions:
<div style="height: 10px"></div>
<ul>
    <li>Arrow up - previous node</li>
    <li>Arrow down - next node</li>
    <li>Arrow right - expand node</li>
    <li>Arrow left - collapse node</li>
</ul>

This property can be defined during object creation:
<textarea class="javascript">
let sidebar = new w2sidebar({
    name : 'sidebar',
    keyboard : false,
    nodes : [
        { id: 'id-1', text: 'Level 1', hidden: true },
        { id: 'id-2', text: 'Level 2', expanded: true, nodes: [
            { id: 'id-2-1', text: 'Level 2.1' },
            { id: 'id-2-2', text: 'Level 2.2' }
        ]},
        { id: 'id-3', text: 'Level 3' }
    ]
});
</textarea>

Or any time after the sidebar has been created:

<textarea class="javascript">
w2ui.sidebar.keyboard = true;
</textarea>

Internally, the feature is implemented by <a href="w2utils.keyboard" class="method">w2utils.keyboard</a> object.

If there more then one sidebar on the screen and all of them have <span class="argument">.keyboard</span> set to true, then the last sidebar
where user selects a record will active keyboard listener.